Kurzfassung in Englisch

This dissertation aims at investigating the potentials, the possibilities, and the limitations of dynamic visualisations, more specifically of on-screen videos, as a learning tool. On-screen videos are a special variant of videos that display what is happening on a computer screen. Examples of the use of on-screen videos might be a demonstration of how to use a new computer application or participate in a multimedia learning environment. The on-screen videos used in this dissertation were designed as modelled worked-out examples.
In two experiments the effects of certain instructional design features implemented in on-screen videos were analysed. Thereby, immediate and mid-term learning results, motivation and transfer were assessed. Both experiments used the ‘acquisition of computer application skills’ learning domain, for which on-screen videos are a highly convenient learning tool as they show how to perform tasks within an authentic environment. A common criticism of instructional videos is that a framework for designing and using visualisations is missing. As a result, knowledge may only be acquired on a short-term basis rather than maintained over time. The theoretical background used here builds on observational learning, research on example-based learning and on multimedia learning. These approaches were employed to determine the instructional procedures that foster learning. In Experiment 1 a special focus was put on investigating two different instructional design variants that intended to make the single solution steps in the computer application salient. These instructional design variants supported the learners in the acquisition of meaningful building-blocks for problem solving, instead of providing them with fixed chains of problem solving steps that can only be applied to similarly constructed problems. Within a 2x2 design, two different methods of segmentation were employed using the on-screen videos. A ‘Label’ for every solution step within a task was presented and further indicated to the learner the following step. The second experimental condition, called ‘Pacing’, was related to the application flow. This consisted of an interactive click-button set at the crucial point of each step. Learners had to pay attention and click there, or the video would stop. This was done in order to avoid the typical “couch potato” style of watching videos in which learning content is passively and superficially processed. The on-screen video conditions were also compared to the standard introduction to the computer application, which follows a learning-by-doing approach with few animations. 101 students took part in Experiment 1. Learning success was measured with a declarative knowledge test (multiple choice/open questions) and a procedural knowledge test consisting of problems to be solved. The results showed that on-screen videos are a particularly successful learning tool in comparison to a standard introduction to the computer application. In other words, learning-by-observation was more effective than the standard introduction. However, a learning goal dependency was found: Those learning with Labelling substantially improved declarative learning outcomes, whereas those learning with Pacing enhanced procedural knowledge. Acceptance and motivation were about equal in all conditions. A very positive result was that learning outcomes could be maintained over time: At a follow-up test three days later, declarative knowledge was even better then at the post-test taken immediately following the experiment.
A restriction of the findings from Experiment 1 was that far transfer could not be fostered. Therefore, Experiment 2 was conducted in which short Practices were inserted in order to foster transfer. In terms of ACT-R theory (Anderson, 1983) the compilation and autonomous stage should be fostered. Practice was implemented directly after each video and had the form of so-called guided exploration cards and was added to the 2x2 design with Labelling and Pacing of Experiment 1. These four with-Practice conditions were compared with a non-Practice condition. 103 learners took part in the experiment, where declarative and procedural knowledge were once again assessed. With respect to declarative knowledge, neither a significant effect for Practice nor for the instructional design variants was found. However, the Labelling group again showed the tendency to be the group demonstrating the most favourable results. With respect to procedural knowledge, significant effects for Practice and for Labelling on far transfer were found. With Practice, the effect of the interactive design variant Pacing was diminished; only Labelling had an additional positive effect on the procedural learning outcomes. In addition, procedural knowledge could be maintained over time. The time period until the delayed post-test was extended to one week. Like in Experiment 1, acceptance and motivation did not differ between the different learning conditions.
To summarise the findings, on-screen videos enriched with instructional design features constitute a very effective learning tool. The selection of an instructional design variant ideally depends on the learning goal. In any case, it is recommended to integrate Labelling and to name each meaningful solution step of the solution procedure. If learning takes place solely by observation, declarative knowledge will be fostered. In combination with Practice, procedural knowledge is generally, along with far transfer, enhanced. If Practice is not part of the learning environment, Pacing in the form of an interactive click button set at the crucial point of a step should be integrated to ensure general procedural knowledge is attained.